Acknowledgements

I acknowledge support from the Swiss National Science Foundation (grant 20-37741.93) for developing the mesoscale numeric model Metphomod . I also wish to thank everybody who supported me to create the model. Werner Eugster (University of Bern, Switzerland) assisted me in the preparation of this publication. He wrote a module, which calculates the position of the sun for Metphomod , and supported me in implementing the soil and the deposition modules. Alain Clappier introduced me to the theory of the finite volume technique and gave me important suggestions for the implementation of the fluid dynamics module. Alberto Martilli (Swiss Federal Technical Institute, Lausanne) supported me in the implementation of the k- $\epsilon$ turbulence parametrization, Frank Kirchner (Swiss Federal Technical Institute, Lausanne) in the application of the RACM chemical mechanism. Urs Neu and Beat Ihly (both University of Bern), discussed preliminary model results with me, and helped to find programming and conceptual errors. Alex Leuenberger, and Matthias Liechti (University of Bern) and Thomas Künzle, Peter Mühlemann and Ueli Joss (Meteotest, Bern) applied the model to different episodes and gave valuable propositions to further improvements. I also acknowledge the support and guidance Prof. Heinz Wanner (University of Bern) gave me during this project.